Bulk quantities of defect-free silicon (Si) nanowires with nearly uniform diameters ranging from 40 to 50 angstroms were grown a length several micrometers supercritical fluid solution-phase approach. Alkanethiol-coated gold nanocrystals (25 in diameter) used as seeds direct one-dimensional Si crystallization solvent heated and pressurized above its critical point. The orientation the produced this method could be controlled reaction pressure. Visible photoluminescence due quantum...

Abstract Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, rational design active has been hampered by lack understanding mechanism on perovskite surfaces. Key parameters that have overlooked include role oxygen vacancies, B–O bond covalency, redox activity lattice species. Here we present a series cobaltite perovskites where covalency Co–O concentration vacancies controlled through Sr 2+...

Carbon dioxide in the liquid and supercritical fluid states is useful as a replacement for toxic organic solvents. However, nonvolatile hydrophilic substances such proteins, ions, most catalysts are insoluble. This limitation was overcome by formation of aqueous microemulsion droplets carbon dioxide-continuous phase with nontoxic ammonium carboxylate perfluoropolyether surfactant. Several spectroscopic techniques consistently indicated that properties approach those bulk water. The protein...

A new synthetic method was developed to produce robust, highly crystalline, organic-monolayer passivated silicon (Si) nanocrystals in a supercritical fluid. By thermally degrading the Si precursor, diphenylsilane, presence of octanol at 500 degrees C and 345 bar, relatively size-monodisperse sterically stabilized ranging from 15 40 diameter could be obtained significant quantities. Octanol binds nanocrystal surface through an alkoxide linkage provides steric stabilization hydrocarbon chain....

Organic itraconazole (ITZ) solutions were mixed with aqueous to precipitate sub-300 nm particles over a wide range of energy dissipation rates, even for drug loadings as high 86% (ITZ weight/total weight). The small particle sizes produced the stabilizer poloxamer 407, which lowered interfacial tension, increasing nucleation rate while inhibiting growth by coagulation and condensation. highest rates slowest found at temperatures below 20 °C increased surfactant concentration Reynolds number...

Photothermal therapy is a noninvasive, targeted, laser-based technique for cancer treatment. During photothermal therapy, light energy converted to heat by tumor-specific photoabsorbers. The corresponding temperature rise causes localized destruction. For effective treatment, however, the presence of photoabsorbers in tumor must be ascertained before and thermal imaging performed during therapy. This study investigates feasibility guiding using photoacoustic detect monitor elevation. carried...

Perovskites are of great interest as replacements for precious metals and oxides used in bifunctional air electrodes involving the oxygen evolution reaction (OER) reduction (ORR). Herein, we report synthesis activity a phase-pure nanocrystal perovskite catalyst that is highly active OER ORR. The mass LaNiO3, synthesized by calcination rapidly dried nanoparticle dispersion supported on nitrogen-doped carbon, demonstrated to be nearly 3-fold 6 nm IrO2 exhibits no hysteresis during evolution....

The ability to design and characterize uniform, bimetallic alloy nanoparticles, where the less active metal enhances activity of more metal, would be broad interest in catalysis. Herein, we demonstrate that simultaneous reduction Ag Pd precursors provides Ag-rich AgPd nanoparticles (~5 nm) with high activities for oxygen reaction (ORR) alkaline media. particles are crystalline uniformly alloyed, as shown by X-ray diffraction probe corrected scanning transmission electron microscopy. ORR mass...

We present a series of perovskite electrocatalysts that are highly active for both the oxygen evolution reaction (OER) and reduction (ORR) in an aqueous alkaline electrolyte. Lanthanum-based perovskites containing different transition metal sites (LaBO3, B = Ni, Ni0.75Fe0.25, Co, Mn) synthesized by general colloidal method, yielding phase pure catalysts homogeneous morphology surface area (8–14 m2/g). Each perovskite's ability to catalyze OER ORR is examined using thin film rotating disk...

Urea electrooxidation has attracted considerable interest as an alternative anodic reaction in the electrochemical generation of hydrogen due to both lower potential required drive and also possibility eliminating a potentially harmful substance from wastewater during fuel production. Nickel nickel-containing oxides have shown activities comparable those precious-metal catalysts for urea alkaline conditions. Herein, we investigate use nanostructured LaNiO3 perovskite supported on Vulcan...

The electrolysis of water is global importance to store renewable energy and the methodical design next-generation oxygen evolution catalysts requires a greater understanding structural electronic contributions that give rise increased activities. Herein, we report series Ruddlesden-Popper La0.5Sr1.5Ni1-xFexO4±δ oxides promote charge transfer via cross-gap hybridization enhance electrocatalytic splitting. Using selective substitution lanthanum with strontium nickel iron tune extent which...

Abstract Consumption of unsafe water is a major cause morbidity and mortality in developing regions. Pasteurizing or boiling to remove pathogens energy‐intensive often impractical off‐grid communities. Therefore, low capital cost, rapid energy‐efficient disinfection methods are urgently required address global challenges safe access. Here, anti‐bacterial hydrogels (ABHs) with catechol‐enabled molecular‐level hydrogen peroxide generators quinone‐anchored activated carbon particles designed...

Interfacial evaporation using porous hydrogels has demonstrated highly effective solar performance under natural sunlight to ensure an affordable clean water supply. However, it remains challenging realize scalable and ready-to-use hydrogel materials with durable mechanical properties. Here, self-assembled templating (SAT) is developed as a simple yet method fabricate large-scale elastic evaporators excellent desalination performance. The interconnected structure of the low tortuosity...

Interfacial solar vapor generation (SVG) is regarded as a promising and sustainable strategy for clean water production. While many materials have demonstrated excellent evaporation rates under one sun, it remains challenging to design evaporators without compromising SVG performance in high-salinity brines (≥10 wt %). Herein, polyzwitterionic hydrogels (PZHs) are proposed novel platform desalination. Taking advantage of the unique anti-polyelectrolyte effects, PZHs can trap salt ions from...

The cloud points of various amorphous polyether, polyacrylate, and polysiloxane homopolymers, a variety commercially available block copolymers, were measured in CO2 at temperatures from 25 to 65 °C pressures ca. 1000−6000 psia. Almost without exception, the solubility polymers increases with decrease cohesive energy density, or likewise, surface tension polymer. With this tension, polymer density becomes closer that CO2. Consequently, is governed primarily by polymer−polymer interactions,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModification of supercritical fluid phase behavior using polar cosolventsJ. M. Dobbs, J. Wong, R. Lahiere, and K. P. JohnstonCite this: Ind. Eng. Chem. Res. 1987, 26, 1, 56–65Publication Date (Print):January 1987Publication History Published online1 May 2002Published inissue 1 January 1987https://pubs.acs.org/doi/10.1021/ie00061a011https://doi.org/10.1021/ie00061a011research-articleACS PublicationsRequest reuse permissionsArticle...

Abstract Polymer microspheres and fibers are formed with a versatile new process, precipitation compressed fluid antisolvent. By spraying 1 wt. % polystyrene in toluene solution into CO 2 through 100‐μm nozzle, diameters from 0.1 to 20 μm as the density decreases 0.86 0.13 g/cm 3 . The uniform submicron spheres produced at high due part rapid atomization by large intertial low interfacial forces. Fibers, without microporosity, obtained higher polymer concentrations where viscous forces...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolute partial molal volumes in supercritical fluidsC. A. Eckert, D. H. Ziger, K. P. Johnston, and S. KimCite this: J. Phys. Chem. 1986, 90, 12, 2738–2746Publication Date (Print):June 1, 1986Publication History Published online1 May 2002Published inissue 1 June 1986https://pubs.acs.org/doi/10.1021/j100403a036https://doi.org/10.1021/j100403a036research-articleACS PublicationsRequest reuse permissionsArticle Views438Altmetric-Citations268LEARN ABOUT...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTWater-in-Carbon Dioxide Microemulsions with a Fluorocarbon-Hydrocarbon Hybrid SurfactantKristi Harrison, Jacqueline Goveas, Keith P. Johnston, and Edgar A. O'Rear IIICite this: Langmuir 1994, 10, 3536–3541Publication Date (Print):October 1, 1994Publication History Published online1 May 2002Published inissue 1 October 1994https://pubs.acs.org/doi/10.1021/la00022a028https://doi.org/10.1021/la00022a028research-articleACS PublicationsRequest reuse...

Abstract The local compositions of supercritical fluid carbon dioxide and a cosolvent about solute at infinite dilution have been estimated for the first time using spectroscopic measurements. was phenol blue, bulk concentrations cosolvents n ‐octane, acetone, ethanol, methanol ranged from 0 to 100 mol%, pressure 80 300 bar. In each case, clusters solvent are enriched in cosolvent. Solubility data measured blue CO 2 with without regressed an augmented van der Waals‐density‐dependent...